Strategy:
Jane Canary is a GREAT companion for Privateer's, if you train her right! True Grit is her best aspect, which allows her to strike back against Musketeers. True Grit 2 is a must, and you may even want to give her rank 3 as well, which can stun Musketeer that attacks her! With the addition of Zeena, it may be in your interest to, if you're a Privateer, swap out El Toro for her in PvP matches - yes, she's one of those few companions that are actually PvP material!

Be sure to attack enemies with her that have either Quick Draw or True Grit. Her normal attack will go off, followed by a True Grit - consecutive True Grits, if the enemy uses Burst Fire. Using enemy Epics is a technique that is important for certain companions, and I find Jane Canary to be one of them. She isn't meant to fire off at the enemy's El Toro (who might actually dodge her) before he can approach - if you give her Overwatch, which I also recommend, it can take a hit at him or other melee enemy units while she is still focusing on dropping Musketeers. Just like Buffalo Bill, you should be trying to drop the enemy before they can drop you. She might be damaged a bit when the enemy's Bonnie Anne is taken out, but eliminating a huge damage dealer such as her from the match is essential.

In standard PvE, she isn't as effective, but I still keep her on my first page and may even choose her in an Epic battle when the boss is a Musketeer. Epic-wise, give her either True Grit 3 and Overwatch OR True Grit 2, Oerwatch, and Double Tap - I recommend the True Grit 3 route, but if you want her as your finisher and don't care about the stun too much, feel free to train Double Tap on her.